Using the calculator
How to use the mold remediation cost calculator.
Use this calculator as a planning tool before you talk to a contractor. It gives a low, typical, and high range so you can compare quotes against a visible set of assumptions instead of relying on one national average.
Start with the inputs you know.
- Enter your repair details. Select the repair type, scope, and any variables that match your situation. The more accurate the inputs, the closer the range will be to a real contractor quote.
- Adjust for severity and access. The calculator adjusts the base cost for condition severity and site access. If you are not sure, leave the defaults — they reflect the most common scenario.
- Review low, typical, and high. The output gives three numbers. Low reflects minimal scope. Typical reflects the most common project. High reflects complex conditions or larger access requirements.
- Bring the range to your contractor conversations. If a quote lands above the high or well below the low, ask the contractor to walk through their scope assumptions. A well-scoped quote rarely falls outside the range.
What changes the price.
The largest price swings usually come from repair method, measured severity, access, and what the quote excludes. For mold remediation, these are the main factors to review:
- Affected square footage, since remediation is priced around $10 to $25 per square foot
- Location and access: a bathroom wall, basement, crawl space, attic, or HVAC system
- Whether growth is surface-level or inside wall cavities, insulation, and framing
- Containment, negative air, and HEPA filtration needs for the work area
- The moisture source repair and post-remediation clearance testing, which are often separate line items
How to read the estimate range.
The low range, around $500, reflects minimal scope and favorable site conditions. The typical range, around $2,350, is the most useful comparison point for an average project. The high range, around $15,000 or more, is where complex conditions, difficult access, or larger scope start to matter.
Most professional remediations run $1,200 to $3,750, with a national average near $2,300 and pricing around $10 to $25 per square foot of affected area. A small contained patch can stay near $500, while whole-house growth after major water intrusion commonly reaches $10,000 to $30,000.
Common project scenarios.
- Small contained patch: $500 to $1,500. Surface growth in one spot, such as a bathroom wall or window, with simple containment and an accessible work area.
- Standard single-area remediation: $1,200 to $3,750. One room or zone with containment, HEPA filtration, removal of affected drywall or insulation, and cleaning, at roughly $10 to $25 per square foot.
- Attic, basement, or crawl space spread: $1,500 to $6,000. Growth across a larger or harder-to-access area. A full attic with affected insulation or sheathing can climb toward $15,000.
- Whole house or major infestation: $10,000 to $30,000. Widespread growth after major water intrusion, usually involving multiple rooms, wall cavities, and coordinated rebuild work.
What may not be included.
- Fixing the moisture source: the leak, drainage, ventilation, or humidity problem
- Independent pre-testing and the written remediation protocol
- Post-remediation clearance testing by an independent party
- Rebuilding removed drywall, insulation, flooring, and finishes
- HVAC system cleaning unless the scope specifically includes it
Use the number in contractor conversations.
The estimate is a reference point, not a final answer. If a contractor quote lands far above the high range or unusually far below the low range, ask what scope assumptions explain the difference.
- Is the inspection and testing independent from the company doing the remediation?
- What is the affected square footage, and how did you measure it?
- What containment and HEPA filtration will be used, and how will the work area be isolated?
- What is being removed versus cleaned, and what happens if you find more growth inside the walls?
- Who fixes the moisture source, and is it in this quote?
Read the Mold Remediation guideSee the full cost breakdownPrepare a quote request